X-Git-Url: http://git.megacz.com/?p=ghc-base.git;a=blobdiff_plain;f=Control%2FConcurrent%2FMVar.hs;h=2fda9f79c8324722bae37a3a363600ea12552eee;hp=3a382946f2d2f718a5d63e02aba2e6f2df91f0f0;hb=8557ebbf1af0fa297db4bd3ee30d7c6e289fdca7;hpb=245a3e3e650e1b110f620e39925bfb0cc9b93002

diff --git a/Control/Concurrent/MVar.hs b/Control/Concurrent/MVar.hs
index 3a38294..2fda9f7 100644
--- a/Control/Concurrent/MVar.hs
+++ b/Control/Concurrent/MVar.hs
@@ -61,6 +61,13 @@
 -- in an 'MVar' to the appropriate normal form, or utilize a strict
 -- MVar provided by the strict-concurrency package.
 --
+-- * Ordering
+--
+-- 'MVar' operations are always observed to take place in the order
+-- they are written in the program, regardless of the memory model of
+-- the underlying machine.  This is in contrast to 'IORef' operations
+-- which may appear out-of-order to another thread in some cases.
+--
 -- * Example
 --
 -- Consider the following concurrent data structure, a skip channel.